Req #78766 [Opn->Nab]: date('Y-m-d', '-1 month') don't work as expected n day 31

Edit report at https://bugs.php.net/bug.php?id=78766&edit=1 ID: 78766 Updated by: requinix@php.net Reported by: gabrielklasso at gmail dot com Summary: date('Y-m-d', '-1 month') don't work as expected n day 31 -Status: Open +Status: Not a bug Type: Feature/Change Request Package: Date/time related Operating System: Any PHP Version: Irrelevant Block user comment: N Private report: N New Comment: It isn't rounding. 2019-10-31 - 1 month = 2019-09-31 (literally 10-1=9) which overflows to 2019-10-01. If you have a specific desired behavior in mind to deal with different month lengths then you need to write specific code to make it happen that way. Previous Comments: ------------------------------------------------------------------------ [2019-10-31 14:39:56] gabrielklasso at gmail dot com Description: ------------ When I run date('m', '-1 month'), I expect to get the number of the previous month, but it is not what always happen. Today is 2019-10-31, and when I run it I got '10'. To understand better what is happening, I tried to run date('Y-m-d', '-1 month') and I got '2019-10-01'. I believe it is because there is no day 2019-09-31, so it rounds up. But IMO it should round down in this case. Test script: --------------- $lastMonth = date('m', '-1 month'); echo $lastMonth; Expected result: ---------------- '9' Actual result: -------------- '10' ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=78766&edit=1